Soap bars, as originally made and sold, are sized to be held in one's hand; but use of a bar with water reduces its size eventually to something too small and/or too pliable for gripping when wet and slippery. Waste is common then, with such soap bar ends frequently merely being thrown away or being washed down the drain.
It is possible to squeeze several small wet soap bar ends together, such as in one's hand, to define a larger usable bar. Lines between the separate bar ends remain in the newly formed bar, and the overall shape of such a bar frequently is glob-like; each detracting from the appeal of the bar.